
"The 'Flynn effect' is a surprising finding, identified by James R. Flynn, that IQ test scores have significantly increased from one generation to the next over the past century. Flynn now brings us an exciting new book which aims to make sense of this rise in IQ scores and considers what this tells us about our intelligence, our minds and society. Are We Getting Smarter? features fascinating new material on a variety of topics including the effects of intelligence in the developing world; the impact of rising IQ scores on the death penalty, cognitive ability in old age and the language abilities of youth culture; as well as controversial topics of race and gender. He ends with the message that assessing IQ goes astray if society is ignored. As IQ scores continue to rise into the twenty-first century, particularly in the developing world, the 'Flynn effect' marches on"
http://www.amazon.com/dp/1107609178
the latest nonfiction book by an expert author, and I'm really liking it a lot. I highly recommend at least one book by Flynn for your summer reading.
The article doesn't give much information
so maybe some readers here will appreciate more information. A recent book that goes into great detail about what the subtest scores of IQ tests show about what happens to people as they age is Are We Getting Smarter?: Rising IQ in the Twenty-First Century by James R. Flynn,
http://www.amazon.com/dp/1107609178/learninfreed
a scholar who has been researching IQ test raw score trends and what they mean for more than thirty years. Flynn has discovered that people who were the brightest (highest in IQ) at younger ages grow old with a pattern of decline that is more steep for their strongest abilities than people who are nearer the average in IQ, a phenomenon he calls the "bright tax." Commentary on that observation
http://www.guardian.co.uk/books/2012/sep/28/are-we-getting-s...
http://www.jasoncollins.org/2012/12/the-bright-tax/
will get you started in thinking about the issue, but I think any Hacker News reader interested in research on human intelligence really owes it to himself or herself to read Flynn's latest book in full, as I finished doing last weekend.
All of James R. Flynn's books are readable and thought-provoking, full of information you can't find anywhere else. Here is what the late Arthur Jensen said about Flynn back in the 1980s: "Now and then I am asked . . . who, in my opinion, are the most respectable critics of my position on the race-IQ issue? The name James R. Flynn is by far the first that comes to mind." Modgil, Sohan & Modgil, Celia (Eds.) (1987) Arthur Jensen: Concensus and Controversy New York: Falmer. Here's what Charles Murray says in his back cover blurb for Flynn's book What Is Intelligence?: "This book is a gold mine of pointers to interesting work, much of which was new to me. All of us who wrestle with the extraordinarily difficult questions about intelligence that Flynn discusses are in his debt." As N. J. Mackintosh (IQ and Human Intelligence 1998, p. 104) writes about the data Flynn found: "the data are surprising, demolish some long-cherished beliefs, and raise a number of other interesting issues along the way." Flynn has earned the respect and praise of any honest researcher who takes time to read the scholarly literature on human intelligence. Robert Sternberg, Ian Deary, Stephen Pinker, Stephen Ceci, Sir Michael Rutter, and plenty of other eminent psychologists recommend Flynn's research.
Another comment I can make about this blog post is that right now the Baby Boom has aged fully into middle age, and is beginning to age into old age, so the largest population cohort in American history until recently will increasingly demand attention to the issues of aging. The Baby Boom, because it is a numerous population cohort, has much influence on United States society, and that's why "classic rock" has never ceased to have radio airplay since that genre of music was first released as top 40 hits. Since millions of Americans are aging, but still think of themselves as young people belonging to a generation of young people, we can expect more blog posts and other popular writings on the topic of changes in individual intelligence in the aging process, and we may as well read sound research on the topic. Another good popular book with a lot of information on human intelligence over the course of the lifespan is IQ Testing 101 by Alan S. Kaufman.
http://www.amazon.com/IQ-Testing-101-Psych/dp/0826106293/lea...
http://www.popsci.com/science/article/2012-11/are-people-get...
that wasn't part of the first wave of gee-whiz stories based on Crabtree's press release, but which actually interviewed other knowledgeable experts to provide perspective on the claims. Reading the Popular Science article "Are People Getting Dumber? One Geneticist Thinks So" linked above, originally submitted to Hacker News by user omnisci
http://news.ycombinator.com/item?id=4811697
and reading the article kindly submitted here by vectorbunny helps to clear up some of the misconceptions sparked by the many articles based on Crabtree's press release.
What I've noticed about this widely covered story is that Crabtree has certainly mastered the Science News Cycle
http://www.phdcomics.com/comics/archive.php?comicid=1174
by making a press release that has had uptake from dozens of news outlets. But none of those news outlets seem to have reporters on staff who are competent to judge the genetics issues involved, or who even know sources in the Behavior Genetics Association. (The article kindly submitted here has better sourcing and analysis than most of the previous articles based on the same press release that I have seen, as author Rob Brooks has actual expertise in the subject, and took care to think through Crabtree's arguments before rushing to print.)
I had earlier shared links to some of the first stories on this issue with friends in the Behavior Genetics Association (I'm part of the Facebook group for the association). Gerald Crabtree has some interesting institutional affiliations and previous accomplishments,
http://www.hhmi.org/research/investigators/crabtree_bio.html
but he is not leading researcher on the genetics of human intelligence. One of the Behavior Genetics Association scientists commented, "I don't know why Crabtree is wasting his time writing about this when he can do such great scientific work."
I have met most of the researchers who are currently active in research on the genetics of human intelligence at a meeting of the International Society of Intelligence Research and at events sponsored by researchers in the Minnesota Twin Families Study in my town. They don't take Crabtree's approach to these sensitive issues.
Another comment already posted here mentions the writings of James R. Flynn. Readers interested in more detail about historical trends in human intelligence are well advised to read James R. Flynn's new book Are We Getting Smarter? Flynn's book deals with much more recent times (just the last century) but has the advantage of being based on actual IQ tests.
http://www.amazon.com/dp/1107609178
http://www.cambridge.org/us/knowledge/isbn/item6835805/Are%2...
http://online.wsj.com/article/SB1000087239639044403240457800...
http://www.guardian.co.uk/books/2012/sep/28/are-we-getting-s...
Flynn is very well respected among behavior geneticists as a "truth-seeker" for his careful research work.
However the author also posits that whether intelligence is increasing is still controversial and difficult to prove conclusively.
[1] Are We Getting Smarter?: Rising IQ in the Twenty-First Century https://books.google.com/books?id=Z_-ykOVpRccC
I'm curious as to what HN thinks about this.
Since you asked, I'll say that Crabtree has certainly mastered the Science News Cycle
http://www.phdcomics.com/comics/archive.php?comicid=1174
by making a press release that has had uptake from dozens of news outlets. But none of those news outlets seem to have reporters on staff who are competent to judge the genetics issues involved, or who even know sources in the Behavior Genetics Association. (The article you have kindly submitted has better sourcing and analysis than most of the previous articles based on the same press release that I have seen, as the reporter took more care before rushing to print.) I have friends in the Behavior Genetics Association (I'm part of the Facebook group for the association), and I've already asked them about this. Gerald Crabtree has some interesting institutional affiliations and previous accomplishments,
http://www.hhmi.org/research/investigators/crabtree_bio.html but he is not leading researcher on the genetics of human intelligence--I have met most of those at a meeting of the International Society of Intelligence Research. If I saw more discussion of this idea in the actual science online sites rather than just in gee-whiz popular articles, I would think that there is more "there" here.
Have you seen reviews of James R. Flynn's new book Are We Getting Smarter? Flynn's book deals with much more recent times (just the last century) but has the advantage of being based on actual IQ tests.
http://www.amazon.com/dp/1107609178
http://www.cambridge.org/us/knowledge/isbn/item6835805/Are%2...
http://online.wsj.com/article/SB1000087239639044403240457800...
http://www.guardian.co.uk/books/2012/sep/28/are-we-getting-s...
Flynn is very well respected among behavior geneticists for his careful research work.
http://www.cambridge.org/gb/knowledge/isbn/item6835805/?site...
http://www.amazon.com/Are-We-Getting-Smarter-Twenty-First/dp...
(The three expert reviewers shown on Amazon are all very impressive researchers on human intelligence in their own right, so their joint endorsement of Flynn's book carries a lot of weight for people like me who follow the research.)
Here is what Arthur Jensen said about Flynn back in the 1980s: "Now and then I am asked . . . who, in my opinion, are the most respectable critics of my position on the race-IQ issue? The name James R. Flynn is by far the first that comes to mind." Modgil, Sohan & Modgil, Celia (Eds.) (1987) Arthur Jensen: Concensus and Controversy New York: Falmer.
AFTER EDIT: Replying to another top-level comment:
I don't understand how anyone could not have an emotional response being told 'your IQ is x'.
People have emotional responses to most statements about themselves that they think are overall evaluations. Some of those emotional responses are more warranted than others. Devote some reading time to the best literature on IQ testing (besides the book under review in this thread, that would include Mackintosh's second edition textbook IQ and Human Intelligence
http://www.amazon.com/IQ-Human-Intelligence-Nicholas-Mackint...
and the Sternberg-Kaufman Cambridge Handbook of Intelligence,
http://www.amazon.com/Cambridge-Handbook-Intelligence-Handbo...
both recently published). Any of these books will help readers understand that IQ tests are samples of learned behavior and are not exhaustive reports on an individual's profile of developed abilities.
AFTER ANOTHER EDIT:
Discussion of heritability of IQ, a reliable indicator of how much discussants read the current scientific literature on the subject, has ensued in some other subthreads here. Heritability of IQ has nothing whatever to do with malleability (or, if you prefer this terminology, controllability) of human intelligence. That point has been made by the leading researchers on human behaviorial genetics in their recent articles that I frequently post in comments here on HN. It is a very common conceptual blunder, which should be corrected in any well edited genetics textbook, to confuse broad heritability estimates with statements about how malleable human traits are. The two concepts actually have no relationship at all. Highly heritable traits can be very malleable, and the other way around.
Johnson, Wendy; Turkheimer, Eric; Gottesman, Irving I.; Bouchard Jr., Thomas (2009). Beyond Heritability: Twin Studies in Behavioral Research. Current Directions in Psychological Science, 18, 4, 217-220
http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...
is an interesting paper that includes the statement "Moreover, even highly heritable traits can be strongly manipulated by the environment, so heritability has little if anything to do with controllability. For example, height is on the order of 90% heritable, yet North and South Koreans, who come from the same genetic background, presently differ in average height by a full 6 inches (Pak, 2004; Schwekendiek, 2008)."
Another interesting paper,
Turkheimer, E. (2008, Spring). A better way to use twins for developmental research. LIFE Newsletter, 2, 1-5
http://people.virginia.edu/~ent3c/papers2/Articles%20for%20O...
admits the disappointment of behavioral genetics researchers.
"But back to the question: What does heritability mean? Almost everyone who has ever thought about heritability has reached a commonsense intuition about it: One way or another, heritability has to be some kind of index of how genetic a trait is. That intuition explains why so many thousands of heritability coefficients have been calculated over the years. Once the twin registries have been assembled, it’s easy and fun, like having a genoscope you can point at one trait after another to take a reading of how genetic things are. Height? Very genetic. Intelligence? Pretty genetic. Schizophrenia? That looks pretty genetic too. Personality? Yep, that too. And over multiple studies and traits the heritabilities go up and down, providing the basis for nearly infinite Talmudic revisions of the grand theories of the heritability of things, perfect grist for the wheels of social science.
"Unfortunately, that fundamental intuition is wrong. Heritability isn’t an index of how genetic a trait is. A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed. There are many reasons for making this strong statement, but the most important of them harkens back to the description of heritability as an effect size. An effect size of the R2 family is a standardized estimate of the proportion of the variance in one variable that is reduced when another variable is held constant statistically. In this case it is an estimate of how much the variance of a trait would be reduced if everyone were genetically identical. With a moment’s thought you can see that the answer to the question of how much variance would be reduced if everyone was genetically identical depends crucially on how genetically different everyone was in the first place."
The review article "The neuroscience of human intelligence differences" by Deary and Johnson and Penke (2010) relates specifically to human intelligence:
http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neur...
"At this point, it seems unlikely that single genetic loci have major effects on normal-range intelligence. For example, a modestly sized genome-wide study of the general intelligence factor derived from ten separate test scores in the cAnTAB cognitive test battery did not find any important genome-wide single nucleotide polymorphisms or copy number variants, and did not replicate genetic variants that had previously been associated with cognitive ability[note 48]."
The review article Johnson, W. (2010). Understanding the Genetics of Intelligence: Can Height Help? Can Corn Oil?. Current Directions in Psychological Science, 19(3), 177-182
http://apsychoserver.psych.arizona.edu/JJBAReprints/PSYC621/...
looks at some famous genetic experiments to show how little is explained by gene frequencies even in thoroughly studied populations defined by artificial selection.
"Together, however, the developmental natures of GCA and height, the likely influences of gene–environment correlations and interactions on their developmental processes, and the potential for genetic background and environmental circumstances to release previously unexpressed genetic variation suggest that very different combinations of genes may produce identical IQs or heights or levels of any other psychological trait. And the same genes may produce very different IQs and heights against different genetic backgrounds and in different environmental circumstances."